They think they have found an explanation why the temperature near the top of the planet's atmosphere is around a thousand degrees celcius, much higher than could be generated by heating from the sun alone.

The team focused on rapidly moving streams of electrically-charged particles or ions in Jupiter's upper atmosphere and found they were accelerated to several kilometres a second.

This detection of near to supersonic so-called "electrojets" provides direct evidence that high-velocity winds do exist in Jupiter's atmosphere and is a powerful confirmation of current theories.

Scientists had theorised that these ion winds followed Jupiter's aurorae - lights emitted by the planet's upper atmosphere.

These aurorae ring the poles of Jupiter and are much like the Earth's Northern and Southern Lights, only many times more powerful. They are formed when electrons are dragged by the planet's magnetic field into the upper atmosphere.

The auroral region is connected to Jupiter's magnetic field though a giant sheet of plasma - ionised gas and dust - which rotates along with the planet around once every nine hours and 55 minutes.

The researchers from University College London calculate that up to 10 million megawatts of power is required to transfer Jupiter's rotational energy to the plasma sheet and it seems the ultra-strong winds may play a role.

So long as the auroral regions "couple efficiently" with the rest of the planet, the friction created could heat the whole upper atmosphere, the astronomers say.